21201301021 has 4 divisors (see below), whose sum is σ = 21469672000. Its totient is φ = 20932930044.

The previous prime is 21201301007. The next prime is 21201301049. The reversal of 21201301021 is 12010310212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21201301021 - 2⁹ = 21201300509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21201300992 and 21201301010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201301421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134185371 + ... + 134185528.

It is an arithmetic number, because the mean of its divisors is an integer number (5367418000).

Almost surely, 2^21201301021 is an apocalyptic number.

It is an amenable number.

21201301021 is a deficient number, since it is larger than the sum of its proper divisors (268370979).

21201301021 is an equidigital number, since it uses as much as digits as its factorization.

21201301021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268370978.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21201301021 its reverse (12010310212), we get a palindrome (33211611233).

The spelling of 21201301021 in words is "twenty-one billion, two hundred one million, three hundred one thousand, twenty-one".